Mirador viewer

SyntaxError: Unexpected token '<', "<!DOCTYPE "... is not valid JSON

{
  "manifest": {
    "error": "SyntaxError: Unexpected token '<', \"<!DOCTYPE \"... is not valid JSON",
    "id": "https://cdm16022.contentdm.oclc.org/iiif/info/p16022coll246/252/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-b25372c8-4fa3-4640-b4ac-06c0df2485e8",
      "cw-fcf4b2fb-1353-494c-b731-99e3faffa19b"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-0c4d55d5-e646-41f4-82b5-5927312341cc",
    "manifestId": "https://cdm16022.contentdm.oclc.org/iiif/info/p16022coll246/252/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-fcf4b2fb-1353-494c-b731-99e3faffa19b"
  }
}